Nuclear reactor incidents can rapidly subject containment vessels to a variety of harsh conditions including damaging temperature spikes. Equipment, including cables, in such environments are critical to the continued safety and monitoring of the reactor and must retain functionality following exposure to a severe accident condition that can expose such equipment to thermal shocks having temperature spikes of 650° C. or more. Current equipment, including cables, associated with a nuclear reactor are not designed for exposure to such thermal shocks and can include components that would be damaged, or destroyed, by such rapid temperature changes. Consequently, there is a need for a heat shield that can be applied to cables used in nuclear environments to mitigate the impact of thermal shocks and maintain continued operation.